The leader of Vanuatu's Land and Justice Party has called for an investigation into the transfer of a controversial parcel of land claimed by custom landowners.

Just before Christmas, Lands Minister James Bule approved the transfer of a 75-year lease on 2,300 hectares of land to investors.

The parcel of land, overlooking Lelepa Island and the Roi Mata World Heritage Area, is claimed by the Mangaliliu and Lelepa people.

The leader of the Land and Justice Party, Ralph Regenvanu, says he is concerned Lands Minister James Bule and his predecessor, Steven Kasakau, may have misused their power to lease land under the Land Reform Act.

Mr Regenvanu says both ministers have acted against the wishes of traditional landowners.

"It is very disappointing to see a minister like James Bule, who is a senior minister, completely going against the wishes of the custom landowners which is what our constitution says, custom landowners are the ones who should have the total rights over their own land," he said.

Mr Regenvanu has called on Prime Minister Sato Kilman to investigate the transactions.